I am currently working on an application for a client, and they have made an odd request. The request involves putting a custom image as the indicator for the scrollview. I am not even sure if this is possible but if it is can you please let me know how one would go about doing that.
Thanks
UIScrollView streches a small, semi-transparent circle image to generate its scrollbars. You can find this image as the first subview of a UIScrollView:
UIImageView *circle = [scrollView.subviews objectAtIndex:0];
However, as I said this image is stretched, and as far as I can tell, only the alpha values are considered when drawing the scroll bars.
So for example if you're only interested in changing the top/bottom ends of the scroll bar, you can try to change this image. However, I doubt you'll be able to do anything interesting.
A possible solution that comes to mind, and this is only a theory, is to add a custom, transparent UIView on top of a UIScrollView. Then you can hide the default scroll bar (by using showsHorizontalScrollIndicator and showsVerticalScrollIndicator), pass the necessary touch events to the UIScrollView to scroll the content, and draw the scrollbars in your custom view.
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I am writing an application for an event my organization is hosting using Swift. I have an image with the floor layout and want to add buttons to select locations (such as bathrooms, entrances, exits, emergency sections, etc) so that people can click them and information about the location pops up.
I currently have an imageview with the floor layout within a scrollview to allow the user to zoom in and out of the image. When I try to add buttons to the scrollview they don't stay relative to the image when zooming in and out, nor do their size change. I have tried adding constraints on to make the location stay the same when zooming in and out.
It also won't let me relocate the button on the storyboard to be a subview of the imageview. Looking up similar solutions says to add the button programmatically as a subview of the imageview but then it'd be really hard to put the 100+ buttons in the right location. Any suggestions as to how to go about this?
you have no other choice instead of adding by code.. because from code you can add as subview of image view , whereas Storyboard wont add buttons as subviews of imageView, but it will add buttons as subview of Scroll View
I am working in an app in which I need to give feature like Notes App in iphone. as shown in first screen shot , initially , notes leaves a tab before the content starts, I also wanted to do the same and for that when I set Left Content inset (of UITextView) by 25 , it shows like in screenshot 2, here you may see the image also gets shifted. I have set image as background. I don't know how to solve this problem.
I also tried by adding image as subview of UITextview but it won't repeat the lines, while scrolling (image of lines) like notes app.
I'm setting the background of Textview by following code.
[textView setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:#"line_image.png"]]];
Please tell me if I am going wrong or any extra effort needed to get desired output.
Thanks
UITextView is UIScrollView subclass so all relevant delegate method are available for you (e.g. scrollViewDidScroll:) - you can adjust your custom background in that method.
There's very nice post on Dr.Touch blog about recreating Notes app interface - you can get general idea about how it is done from it. Basically what is done there is adding custom view that draws background behind the text view and adjust it in text view's delegate methods and also using KVO on its 'contentSize' property.
#Dinesh gave nice solution but it doesn't sound to be generic as I want to use image of lines instead of drawing them. Image has some special effects that can not be achieved by drawing. So to solve it I created a table view below the textview keeping textview's background transparent. Now just added the image of line to my tableview's custom cell and set content offset of UItableview same as of the scrollview (subview of text view ,refering to the answer of #Vladimir ) .
And used the following code to scroll my tableview with scrolling the textview and got the desired output.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
tableView.contentOffset =scrollView.contentOffset;
}
Keeping my tableview's number of rows at a very large number.
PS: instead of setting the content inset of textview, i set its frame's X position and decreased the width relaively.
I know that I asked a question a few minutes ago, but I want to make a few points clearer before asking for the community's help. I'm new to iOS development, close to finishing my first app. The only thing standing in my way is this UIScrollView. I simply do not understand it, and could use your help.
This is in the detail view controller of a drill-down app with a tab bar. I have approximately 8 fields (for things like phone numbers and such) drawing from a .plist. Obviously, those take up enough room that I could use a little extra real estate. I would guess that it needs to be about the size of two views vertically, but I do not understand how to allocate that sort of space to a UIScrollView. Some tutorials I have read say that you don't even need to define it in the header, which I doubt and do not understand. Additionally, I do not understand how to simply get the app to smoothly scroll up-and down only. Apple's examples have constant move cycles that flip between horizontal pictures.
I doubt it makes very much a difference, but I have an image that is in the background. I'm going to load the view on top of that.
My question is broad, so I don't expect you to take the time to sit down and write out all of the code for me (and I wouldn't ask you to). Just an outline of quick, helpful tips would help me understand how to get this view to load in the context of my project.
Many thanks!
It's fairly simple. Add a UIScrollView to your view. Add your fields and such to the scrollview. In viewDidLoad or somewhere similar, you need to set the contentSize on your scrollview. This is the "virtual" area that will be scrollable. This will generally be larger than the frame of the scrollview. In your case, you indicated it should be roughly double the width.
For instance, if you had a scrollview with a view inside, and you wanted to make sure the entire view is visible via scrolling:
self.scrollView.contentSize = self.contentView.frame.size;
//setting scrollview zoom level
self._scrollview.minimumZoomScale=0.5;
self._scrollview.maximumZoomScale=6.0;
self._scrollview.contentSize=CGSizeMake(320,500 );
you have to outlet scroll view in .h class and #property #synthesis this scroll view.then you can able to scroll up and down,if u want only vertical scrolling ,then u have to go to interface builder and uncheck the horizontal scrolling.
You can set a few settings for your scrollview to limit the scrolling to horizontal or vertical. A few important ones are:
// pseudcode here, start typing "[scrollView " then press escape to get a intelli-sense of all // the things you can set for the scrollview.
// values could be YES/NO or TRUE/FALSE, I can't remember which one but
// I think it's YES/NO. Once you start scrolling, the phone will determine
// which way you're scrolling then lock it to that direction
[scrollView setDirectionalLockEnabled:YES];
// when you slide the view, if enough of the next part of the view is visible,
// the scrollview will snap or bounce the scrollview to fit this new "page".
// think of swiping feature to navigate the iPhone home screens
// to show different "pages" of iphone apps
[scrollView setPagingEnabled:YES];
// as a safe guard, make sure the width of your scrollview fits snuggly with the content
// it is trying to display. If the width is more than necessary to display your table of
// data vertically, sometimes the scrollview will cause the
// horizontal scrolling that you don't want to happen and you get bi-directional scrolling
Just set the content size of UIScrollView after adding all the controls/button/textfields etc. for example you add 10 textfields in UIScrollview then content size of UIScrollView will be
lastTextField.frame.origin.y+lastTextField.frame.size.height+20; 20 is for margin.
That's it let me know if you want to know something more related to your app.
I have a UIToolbar in IB with a custom UIBarButtonItem that is set to an image. The image height is larger than the UIToolbar height. The image does not load for some reason. Attached is a screenshot.
You should avoid using subviews that are larger than the parent view - even if it does work and draws the view outside of the bounds, you cannot always count on it because the clipping is skipped for performance reasons and depending on the drawing order the overlapping part of the subview might be covered later. Second problem is that only the part within the frame of the superview is able to handle the touch events.
As to why you don't see your image, it's probably a different problem, I doubt it has something to do with it going outside the frame. Post your code to get more feedback ;)
I am trying to create an app with horizontal scrolling, so that one would be able to scroll horizontally through a series of images. I watched the WWDC Session 104 video on this, and while they made an interesting app, they flew through the basics of it very quickly.
I understand using the UIScrollView, and that I have to enable paging. After that they say that I should add more views as subviews of the scrollview, but I am not clear on how to do that. I am also not clear on how I add my images to those views.
As you can probably tell I am pretty new at this so any help would be appreciated.
You want to look into UIImageView. It's a view specifically for holding images.
When you add your images, you want to set their rects (probably using initWithFrame: for each UIImageView) so that:
the first image is at 0,0
the second image is at 320,0
third is at 640,0 (etc)
I.e. each image is 320 pixels right of the previous.
The final step is to set the contentSize for your UIScrollView -- this is a CGSize which describes the total size of the scroll view.
If you have 3 images, you would then set it to (320*3) * 480 using e.g.
myScrollView.contentSize = CGSizeMake(320*3, 480);
A lot of people, when they initialize the scroll view, have a for loop or similar which steps through the images they want to display. These for loops tend to look something like this:
CGFloat scrollWidth = 0.f;
for (UIImage *someImage in someNSArrayWithImages) {
UIImageView *theView = [[UIImageView alloc] initWithFrame:
CGRectMake(scrollWidth, 0, 320.f, 480.f)];
theView.image = someImage;
[myScrollView addSubview:theView];
[theView release];
scrollWidth += 320.f;
}
myScrollView.contentSize = CGSizeMake(scrollWidth, 480.f);
This way you'll get things lined up and you'll get the content size for you at the same time.
If you want to make it so that the scroll view "intelligently" scrolls to each image and stops when people slide left/right, you can do myScrollView.pagingEnabled = YES.
Hope that helps get you going.
Assuming you have "infinite" images, putting them all there at or before launch time in a huge UIScrollView will not be an option. (there is a limit to the size of a UIView)
The way I solved it: Make a UIScrollView covering the whole screen. It's content should be a UIView of 3*320 width and 480 height, extending 320px left and 320px right.
Put 3 UIImageView's in it, left, middle and right. Set paging=YES, so the uiscrollview clips to the 3 "pages" you've created.
Make sure your class is the delegate of the uiscrollview, and listen for
-(void)scrollViewDidEndDragging:(UIScrollView*)sv willDecelerate:(BOOL)notFinished
-(void)scrollViewDidEndDecelerating:(UIScrollView*)sv
-(void)scrollViewDidEndScrollingAnimation:(UIScrollView*)sv
and make the appropriate transitions on hitting paging boundaries; shift images and set ContentOffset so you're looking at the center image again.
I suggest you make this first, and only then read on...
Then you will hit on a bug, documented here UIScrollView - (bounces = NO) seems to override (pagingEnabled = YES) and here http://www.iphonedevsdk.com/forum/iphone-sdk-development/935-paging-uiscrollview.html, which makes that you cannot disable bouncing and have paging enabled at the same time. So enable bouncing, and subclass UIScrollView, overruling setContentOffset in there to prevent bouncing. (having bouncing really enabled will make for a rather unusual user experience)
Have a look at Apple's PageControl sample code. It's fairly short and easy to follow so you'll get the gist of setting up a project where multiple view controllers are loaded as you swipe horizontally.
Once you have this setup then it's the view controller's responsibility to load its own content (in your case, an image). You should make sure you understand how to load images first (using threads, etc) before you tackle paging, etc.
Think of it as two independent tasks. The view control is responsible for loading and displaying an image. The scroll view with paging just tells the appropriate view controller when to load itself (it doesn't care what the view controller does once its loaded)
Good luck!